Many devices rely on biometric sensors, such as fingerprint sensors to control user access. For example, a device may include a fingerprint sensor to scan a user's fingerprint and compare the fingerprint scan to a reference image to determine whether the user is granted or denied access.
Conventional optical fingerprint scanners analyze reflected light to perform fingerprint detection. As such, conventional optical fingerprint sensors may be tricked into allowing unauthorized users access to the device. For example, a counterfeit fingerprint (e.g., an image, photo, or sketch of a user's fingerprint) may be presented to the optical fingerprint sensor in place of the user's finger. Due to limitations in analyzing reflected light, a conventional optical fingerprint sensor may be easily deceived by the counterfeit fingerprint.
Thus, there is a need for a fingerprint sensing device with robust protection against false and/or counterfeit fingerprints.